Apparatus for preparing synthetic carbonado diamonds



Jan. 14, 1936. J. H. L. DE BATS APPARATUS FOR PREPARING SYNTHETIC GARBONADO DIAMONDS Filed Jun 20. 1954 2 Sheets-Sheet l \v IIIIIIIMHHHII lmnmn lllll Hil IIIIIHHIIIHII 40 Jan. '14, 1936. J. H. DE BATS 2,027,963

APPARATUS FOR PREPARING SYNTHETIC CARBONADO DIAMONDS Filed June 20, 1934 2 Sheets-Sheet 2 ATTORNEY$ Patented Jan. 14, 1936 UNITED STATES PATENT OFFICE APPARATUS FOR PREPARING SYNTHETIC CABBONADO DIAMONDS "lClalms.

This invention relates to improvements in artificial diamonds and mountings therefor, and more particularly to artificial or synthetic Carbonado diamonds and methods of preparing and mounting same, as well as the improved apparatus therefor.

Carbonado diamonds have been of great value in commercial grinding and drilling operations by reason of their uniform wearing quality coupled with their high-shock resistance, which high-shock resistance is appreciably greater than that obtaining with pure or gem diamonds. The qualities of the Carbonado diamond which provide or give this improved shock-resistance, have never been completely and definitely established, but I believe that these properties are due to the amorphous carbon material in which the diamonds of the Carbonado are naturally embedded.

It is a feature of this invention to provide an improved synthetic diamond mass, comprising particulate gem diamonds embedded in a shockresisting matrix.

It is a further feature of this invention to provide an improved synthetic diamond for industrial purposes, and simulating a natural Carbonado diamond, in which fine diamond particles are embedded in a metal matrix.

Another feature of the present invention is the provision of improved apparatus for preparing synthetic Carbonado diamonds.

It is also a feature of this invention to provide improved apparatus for preparing artificial or synthetic Carbonado diamonds in which a diamond mix is subjected to the action of heat in an inductive electric field and to the concomitant action of centrifugal pressure plus a backing or plunger member.

Another feature of novelty of the present invention resides in the provision of an improved apparatus for preparing synthetic Carbonado diamonds in which a mix of particulate gem diamonds and a bonding material is subjected to the action of a plunger in a centrifuge, while being subjected to the action of an induced electrical field.

These and other desirable features and advantages of the present invention will be described in the specification and illustrated in the accompanying' drawings, a certain preferred mode of operation and apparatus therefor being disclosed by way of example only for, since the underlying principles may be incorporated in other specific mechanical devices, it is not intended to be limited to the ones here shown, except as such limi- Fig. 3 is a partial top plan view, partly in horizontal section, of the structures shown in Figs. 1 and 2;

Fig. 4 is a view similar to Fig. l showing a modiform of apparatus;

Fig. 5 is a vertical section of the apparatus shown in Fig. 4; and

Fig. 6 is a horizontal view, partly in broken section and partly in elevation, of the structure of Fig. 5.

Referring more particularly to the drawings, the form of the apparatus shown in Figs. 1 to 3 comprises a casing lflp'isupporting a coil of an induction furnace element. The casing It! may be apertured to form a central chamber H in which may be disposed a motor 30. Mounted for rotation on the motor 30 may be a centrifugal casting machine construction, designated generally by the numeral 40. The motor and induction furnace members are of usual construction, and will not be described in detail herein, save in the general combination of parts shown.

The centrifuge device 40 includes a base plate or spider 4|, mounted on a shaft 3! of motor 36 and adapted to rotate therewith. Secured-.to the plate or spider member 4| is a copper or other non-magnetic fiat annular metal member 42 having a peripheral upstanding flange 43. An annular cover member 44 is also provided with a peripheral, dished flange 45. The members 42 and 44 are uniform and symmetrical in construction. The member 42' is secured to the spider 4| in any suitable manner, as by means of copper or bronze machine screws, a suitable socket wrench 4lb being used to secure same in place.

The inner faces of the members 42 and 44 are provided with asbestos or other refractory sheathing material 46, forming a protection for the copper or other metal used in the member by retarding the flow of heat from the mold. A facing 41 of carbon is conformed to the membars 42 and 44 interiorly of the asbestos surfacings 46. A. graphite heating chamber 50 is set in or fitted between the members 46, being held therein by counter-sunk screws 48 of copper or other non-magnetic metal. The graphite heating members 50 may be tapped, as indicated, to receive crucible members 5| of quartz or other generally high refractory noncarbonaceous materials or compositions. Other suitable materials may comprise alumina, zirconia, magnesia (including periclase), and the like. These sleeves or crucibles 5| serve to protect the material in the interior thereof from being exposed to carbon or graphite at the high heats maintained in the operation of the induction furnace of which they form a part.

A mass of diamonds 52 is inserted in each of the crucible members 5|, after which a powdered mass 53 of any suitable metallic material is placed in the said members on top of the diamonds. Such materials may include refractory alloys such as tungsten-cobalt alloys, with or without additions of refractory materials, such as tungsten carbide, molybdenum carbide, vanadium carbide, zirconium carbide, and

. other refractory compositions. Highly heat-conductive metals and alloys such as copper, silver, and their alloys may also be used. Plugs 54 are placed in the crucibles and form a sliding fit therewith to prevent the inrush of air to the contents of the crucible during operation. The plugs 54 may be made of a heavy metal, such as tungsten, if it is desired to impose an appreciable pressure on the materials in the crucibles during the heating and consolidating operations. The amount of pressure developed will depend on the speed of the centrifuge, and the weight of the plug, and may vary from a quarter of a ton or less up to 50-100 tons or more.

The improved diamond members or bodies of the present invention are prepared by setting the centrifuge machine in motion, and passing a high frequency current of desired strength and characteristics through the coil of member 20. The inductive field set up by the coil causes the graphite members 50 of the rotating centrifugal machine to be highly heated. which heat is readily transferred to the crucible or mould members 51 formed and inserted therein. The metallic plate members 42 and 44 of the system are protected from the heat of members 50 by the carbon protective members 41 and the asbestos or like refractory protective materials 46. It will be seen that as the mass 53 is subjected to heat it will tend to coalesce and be thrown against and into the particles 52 of diamond or other suitable refractory abrasive materials, thoroughly wetting the same. Back wash or floating out of the diamonds under the high pressures developed is prevented by the presence of the plugs 54 which are preferably of heavy metals although graphite may be used. These plugs not only provide an air-tight seal for the crucibles 5|, but also provide a back pressure for the now consolidated materials in the crucible and prevent separation of the same by them, as indicated above, under a positive pressure.

When the material has coalesced under heat, the current is shut 011 and the machine isallowed. to come'to a stand-still, which takes an appreciable time period, usually of the order of five minutes. Thereafter the coil may be removed from the furnace and the upper portion 44 of the clamping ring for the crucibles is removed. The members 50, which may be made in segments, are then removed and the cooled slugs removed from the crucibles, or if they are interfused therewith, the crucibles are broken up and the slugs or nibs recovered.

The resulting product will be a highly densi fled mass of particulate diamonds embedded in a minimum amount of embedding material, such as any of the refractory alloys recited above. While refractory alloys including carbides and carbide compositions have been cited as advantageous, desirable results have been secured by embedding particulate diamonds in copper, silver, copper-silver alloys, alumina, and the like. Such products are particularly suited for heavy work where appreciable heats are developed, as they can be readily secured to stems or supports of suitable metals, thus providing a desired rapid heat withdrawal.

Referring now to the modifications shown in Figs. 4 to 6, the graphite heating members may be made in arcuate segments, indicated generally by the numeral 60. In these segments, quartz, alumina, periclase, zirconia, carbon or graphite tubes 6| may be mounted. The arcuate graphite members 60 are preferably formed by mating parts 60a and 60b to permit the introduction and withdrawal of the tubes Bl with their reacted and coalesced contents, as will be described more in detail hereinafter. The annular arcuate segments 60 are mounted in a bottom dished support or plate 10 of a suitable non-magnetic material, such as copper. The usual surfacings of asbestos and of carbon 46 and 41 may be provided to cover the entire surface of the plate 10, the members 41 being provided with an annular recess adapted to seat the members 60. The top member 1| is likewise provided with an annular channeled recess adapted to receive the segments 60a of member 60, and is provided with protective coatings 46 and 41. A central aperture 12 is provided in the upper member and through the parts thereof to permit the introduction of suitable molten, plastic or powdered materials which are to be cast in place in the refractory crucibles 61. This member or funnel 12 serves to permit the introduction of a molten, semi-molten, or powdered embedding mass which is centrifuged into the tubes 6| to embed and compact the diamonds 13 contained therein.

In practice, the diamonds are inserted in the tubes 6|, and the latter set up in the recesses between the graphite blocks. Afterwards, the cover, with the protective carbon and asbestos facings, is disposed thereover and securely clamped to the bottom members in the same manner as indicated in Fig. 2. After the arrangement of parts has been assembled and locked together, the apparatus is set in rotation and current passed through the heating coil 20. The graphite members 60 are heated by the induced current, and transmit the heat to the crucibles 6|. The diamonds contained in the latter are thus preheated. A protective atmosphere may be formed in the interior of the crucibles, as by closing the funnel or inlet 12 of the system, and a non-reactive gas, such as hydrogen, passed into the same. After the diamonds 13 and their containers have been-suitably preheated, a mass of metal, either liquid,

semi-liquid, or in powder form, may be introduced through the funnel 12, and is uniformly and rapidly dispersed and thrown into the several crucible members 6!, as indicated generally by the numerals 14 in the various figures. This material compacts in and about and wets the diamonds I3 forming a substantially unitary mass therewith. When the embedded mass has been introduced, the heating coil is shut off and the motor allowed to come to a standstill. After the machine is stopped the coil is removed and the centrifugal apparatus dismounted. The crucibles 8| are removed and usually broken up to remove the contents. The resulting products may comprise diamonds formed at the end of a shank, and embedded in any suitable metal such as copper, silver, copper-silver alloys, nickel and nickel alloys, iron, steel, refractory-metals, and alloys such as tungsten-cobalt alloys and the like, and refractory compositions, such as tungsten carbide base materials embedded in refractory metals and alloys.

It will now be seen that there has been provided an improved apparatus and method for forming artificial or synthetic diamond masses of the so-called Carbonado type, which masses are generally comprised of particulate diamonds compacted and embedded in a metal mass, the whole being so constituted and arranged as to provide a minimum amount of binder for the diamonds, while at the same time assuring a maximum support and bonding therefor. The products sov prepared, particularly when including metals as binding agents, and more particularly high heat conducting metals, such as copper and silver and their alloys, may be further improved by' providing extensions or shanks of the same alloys or metals whereby to provide a heat reservoir for rapidly withdrawing any heats developed in and around the diamonds embedded in the tips thereof.

While certain novel features of the invention have been disclosed and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and changes may be made by those skilled in the art without departing from the spirit of the invention.

What is claimed is:

1. An improved apparatus for use in making synthetic Carbonado diamonds, comprising a motor having a shaft, a two-part body member mounted on said shaft, said body member being of non-magnetic material, a carbonaceous member disposed between parts of said body member and clamped therein, said carbonaceous member being susceptible of heating by inductive currents, a plurality of crucible members formed in and associated with said carbonaceous heating member and peripherally disposed with respect to the apparatus, and an induction coil disposed externally of the heating member and concentrically therewith whereby to inductively heat the said heating member while the latter is being rotated by the said body member.

2. An improved apparatus for use in making synthetic Carbonado diamonds, comprising a motor having a shaft, a two-part body member mounted on said shaft, said body member being of non-magnetic material, a segmented carbonaceous member disposed between parts of said body member and clamped therein, said carbonaceous member being susceptible of heating by inductive currents, a plurality of crucible members formed in and associated with said carbonaceous heating member and peripherally disposed with respect to the apparatus, and an induction coil disposed externally of the heating member and concentrically therewith whereby to inductively heat the said heating member while the latter is being rotated by the said body member.

3. An improved apparatus for use in making synthetic Carbonado diamonds, comprising a motor having a shaft, a two-part body member mounted on said shaft, said body member being of non-magnetic material, an arcuate, segmented carbonaceous member disposed between parts of said body member and clamped therein, said carbonaceous member being susceptible of heating by inductive currents, a plurality of crucible members formed in and associated with said carbonaceous heating member and peripherally disposed with respect to the apparatus, and an induc tion coil disposed externally of the heating member and concentrically therewith whereby to inductively heat the said heating member while the latter is being rotated by the said body member.

4. An improved apparatus for use in making synthetic Carbonado diamonds, comprising a motor having a shaft, a two-part body member mounted on said shaft, said body member being of non-magnetic material, a split, two-part carbonaceous member disposed between parts of said body member and clamped therein, said carbonaceous member being susceptible of heating by inductive currents, a plurality of crucible members formed in and associated with said carbonaceous heating member and peripherally disposed with respect to the apparatus, and an induction coil disposed externally of the heating member and concentrically therewith whereby to inductively heat the said heating member while the latter is being rotated by the said body member.

5. An improved apparatus for use in making synthetic Carbonado diamonds, comprising a motor having a shaft, a two-part body member mounted on said shaft, said body member being supported by a spider and said body member being of non-magnetic material, a split, twopart carbonaceous member disposed between parts of said body member and clamped therein, said carbonaceous member being susceptible of heating by inductive currents, a plurality of crucible members formed in and associated with said carbonaceous heating member and peripherally disposed with respect to the apparatus, and an induction coil disposed externally of the heating member and concentrically therewith whereby to inductively heat the said heating member while the latter is being rotated by the said body member.

6. An improved apparatus for use in making synthetic Carbonado diamonds, comprising a motor having a shaft, a two-part body member mounted on said shaft, said body member being of non-magnetic material and comprising a dished bottom having an annular recess and a recessed annular top concentric with the bottom and spaced therefrom, a split, two-part carbonaceous member disposed between parts of said body member and clamped therein, said carbonaceous member being susceptible of heating by inductive currents, a plurality of crucible members formed in and associated with said carbonaceous heating member and peripherally disposed with respect to the apparatus, and an induction coil disposed externally of the heating member and concentrically therewith whereby to inductively heat the said heating member while the latter is being rotated by the said body member.

'7. An improved apparatus for use in making synthetic Carbonado diamonds, comprising a motor having a shaft, a two-part body member mounted on said shaft, said body member being 10 being susceptible of heating by inductive cur.-

- rents, a.v plurality of crucible members formed in and associated with said carbonaceous heating member and peripherally disposed with respect to the apparatus, and an induction coil disposed externally of the heating member and concentrically therewith whereby to inductively heat the said heating member while the latter is being rotated by the said bodv member.

JEAN HUBERT LOUIS DE BATS. 

